Strumentazione di A breve termine pecore fetale per multivariata cronica Recordings non anestetizzati
Summary
Il non anestetizzato modello pecore fetale cronicamente strumentato viene utilizzato per studiare lo sviluppo del feto umano in salute e malattia, perché permette l'inserimento chirurgico e manutenzione di cateteri ed elettrodi, ripetitivo prelievi di sangue, iniezione di sostanze, registrazione dell'attività bioelettrica, e imaging in vivo. Si descrivono le procedure necessarie per stabilire questo modello.
Abstract
The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli such as endotoxins, bacteria, umbilical cord occlusions, hypoxia and various pharmacological treatments. The life-saving clinical practices of glucocorticoid treatment in fetuses at risk of premature birth and the therapeutic hypothermia have been developed in this model. This is due to the unique amenability of the non-anesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection, recording of bioelectrical activity, application of electric stimulation and in vivo organ imaging. Here we describe the surgical instrumentation procedure required to achieve a stable chronically instrumented non-anesthetized fetal sheep model including characterization of the post-operative recovery from blood gas, metabolic and inflammation standpoints.
Introduction
Una varietà di modelli animali esistono per lo studio di entrambe le gravidanze normali e compromessi, tra cui roditori da laboratorio, primati non umani e ruminanti domestici. 1,2,3,4,5 La pecora incinta cronicamente strumentato è stato ampiamente utilizzato per 50 anni come un modello di sviluppo del feto umano e le risposte agli stimoli fisiopatologici quali lipopolisaccaride (LPS). 6-10 Le lesioni a seguito di esposizione LPS imitare esattamente quello che si vede nei neonati pretermine con leucomalacia periventricolare, che è dovuto ad un profilo simile maturazione di entrambe le specie. 11, 12
Altre complicazioni della gravidanza sono stati studiati nei minimi dettagli, come la scoperta che i glucocorticoidi prenatali promuovere lo sviluppo del polmone 13-15 e comprendere l'impatto di ritardo di crescita intrauterino (IUGR) sul feto 16,17.
L'uso estensivo del modello pecore fetale è dovuto al unique amenability delle pecore fetale non anestetizzati per l'inserimento chirurgico e manutenzione di cateteri ed elettrodi, consentendo il prelievo di sangue ripetitivo, registrazione dell'attività bioelettrica, applicazione di stimolazione elettrica e in imaging cerebrale vivo. 18 telemetria è anche possibile, anche se utilizzato meno frequentemente tuttavia a causa della maggiore sofisticazione configurare come pure il costo iniziale e di mantenimento. 19
Inoltre, il modello di pecora fetale è molto versatile come molte variazioni di strumentazione sono possibili a seconda delle misure di interesse. Ad esempio, è possibile registrare più di giorni o settimane segnali multivariati in tempo reale, come i movimenti fetali di respirazione, l'attività elettrica del cervello, le risposte cardiovascolari, elettrocardiogramma, il flusso di sangue regionale per una serie di organi con sonde di flusso o microsfere, ecc Grazie a questa versatilità, una vasta gamma di studi sono stati condotti compreso lo sviluppo del cardiSistema ovascular 20,21, ipotalamo-ipofisi-surrene (HPA) 22, lo sviluppo del cervello e lo sviluppo di 23 stati di sonno, in particolare il 24, effetti dell'ipossia / asfissia 25, ipotermia terapeutica 26, infiammazione 6-11, combinazione di entrambi 27, glucocorticoidi 28,29, anti-depressivi 30, displasia broncopolmonare (BPD) 31,32, fetale programmazione 33,34,35,36,37,38,39 o lo sviluppo di nuove modalità di monitoraggio del feto prima e durante il travaglio, per citarne solo alcune aree di indagine. 40,41,42,43
L'obiettivo generale del metodo presentato è quello di mostrare implementazione di base di questo modello versatile. Permette di stabilire una vasta gamma di protocolli sperimentali acute e croniche che studiano la fisiologia e fisiopatologia fetale sul integrativo, organo, cellulari e livello molecolare.
Protocol
Representative Results
Discussion
L'anestetico e le procedure chirurgiche sono presentati che sono necessari per la creazione di un modello animale per lo studio della fisiologia e fisiopatologia fetale: la pecora feto non anestetizzato cronicamente strumentato.
Quattro passi critici all'interno del protocollo devono essere sottolineati. Innanzitutto, passando i cateteri e elettrodi attraverso il fianco materno: è importante che venga effettuata una volta per evitare eventuali lesioni di organi interni. In secondo l…
Offenlegungen
The authors have nothing to disclose.
Acknowledgements
authors gratefully acknowledge funding support from the Molly Towell Perinatal Research Foundation, Canadian Institutes of Health Research (CIHR), and Fonds de Recherche du Québec – Santé (FRQS) (to MGF) and CIHR-Quebec Training Network in Perinatal Research (QTNPR) (to LDD).
The authors wish to thank Esther Simard, Marco Bosa, Carl Bernard and Carmen Movila for technical assistance.
Materials
| ACE Light source | Schott-Fostec | A20500 | |
| Dissecting scissors | Fine Science Tools | 14060 – 11 | |
| Angled dissecting scissors | Fine Science Tools | 15006 – 09 | |
| Scalpel handle | Fine Science Tools | 10003 – 12 | alternating dissecting tool |
| Curved scalpel blades #12 | Fine Science Tools | 10012 – 00 | alternating dissecting tool |
| Bone scissors | Fine Science Tools | 16044 – 10 | |
| S & T suture tying forceps | Fine Science Tools | 00272 – 13 | |
| Dumont SS forceps – angled | Fine Science Tools | 11203 – 25 | |
| Braided silk suture size 6-0 | Teleflex Medical | 07 – 30 – 10 | |
| Medical Tape | transpore | 3M | |
| Ketamine hydrochloride 100 mg/ml | Hospira | NDC 0409 – 2051 – 05 | Final Does is 80 mg/kg |
| Tranqui Ved Injection (xylazine 100 mg/ml) | Vecdo | NDC 50989 – 234 – 11 | Final Does is 10 mg/kg |
| Reactive orange 14 | Sigma – Aldrich | R – 8254 | |
| Ringers Solution Components | Solution is gas equilibrated with 95% O2 and 5% Co2, final pH 7.4 | ||
| Sodium chloride | Sigma – Aldrich | S7653 | Final Concentration: 118 mM |
| Potassium chloride | Fisher Scientific | P217 – 3 | Final Concentration: 4.7 mM |
| Calcium chloride dihydrate | Fisher Scientific | C79 – 500 | Final Concentration: 2.5 mM |
| Potassium phosphate monobasic | Fisher Scientific | P -285 | Final Concentration: 1.2 mM |
| Magnesium sulfate | J.T. Baker | Jan-00 | Final Concentration: 0.57 mM |
| 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES) | Fisher Scientific | BP 310 – 500 | Final Concentration: 5.95 g/L |
| Glucose | Sigma – Aldrich | G8270 | Final Concentration: 5.5 mM |
| LifeWindow | Digicare Biomedical Technology | ||
| CED bioamplifier and ADC units | Cambridge Electronic Design Limited, Unit 4, Science Park, Milton Road, Cambridge CB4 0FE ENGLAND. |
Bioamp: 1902; ADC: micro1401; Data acquisition software: Spike 2, V7.13 | |
| Neurolog analog signal bioamplifier | Digitimer Ltd 37 Hydeway Welwyn Garden City Hertfordshire, AL7 3BE, England |
NL108A | |
| ABL800Flex | Radiometer Canada; 200 Aberdeen Dr, London, ON N5V 4N2 | ||
| Eppendorf 5804R | Eppendorf Canada; 2810 Argentia Road, #2 Mississauga, Ontario, L5N 8L2 |
||
| Arrow Jugular Catheterization Set | Arrow International, Inc., 2400 Bernville Road, Reading, PA 19605 USA | ||
| Atravet | 10 mg/mL | ||
| Diazepam | 5mg/mL | ||
| Ketamine | Ketalar | 100 mg/mL | |
| Propofol | 10 mg/mL | ||
| SurgiVeT | Endotracheal Tubes; Smiths Medical ASD, Inc. St. Paul, MN 55112, USA | ||
| Cook Airway Exchange Catheter with RAPI-FIT Adapters | Cook Critical Care 750, Bloomington IN 47402-0489 USA | ||
| Dispomed Ventilator | Dispomed Ltd., 745 Nazaire-Laurin, Joliette, Quebec J6E 0L6 | ||
| BD Insyte-W | Becton Dickinson, Infusion Therapy Systems Inc., 9450 S State St, Sandy Utah 84070 USA | 22 to 20 G; 1 in [0.9 x 25 mm] to 1.16 in [1.1 x 30 mm] | |
| Edwards Lifesciences Ref: PX272 Pressure monitoring kit with TruWave Disposable Pressure | |||
| LifeWindow LW6000 | Digicare Biomedical Technology 107 Commerce Road, Boynton Beach, FL 33426-9365 USA | ||
| Gaymar | |||
| Babcock | |||
| Polyvinyl catheters | SCI (Scientific Commodities Inc.) | 2 meters | |
| 2-0 Vicryl | |||
| Castroviejo scissors | |||
| electrocardiogram (ECG) | LIFYY, Metrofunk Kabel-Union, Berlin, Germany | four copper electrodes in single sheath, 2 meters | |
| 2-O Vicryl | |||
| 3-0 Vicryl | |||
| PDS II USP | |||
| Trimethoprim sulfadoxine | |||
| Ampicillin | |||
| Stopcock | Argon Medical, Cat 041220001A | Double 4-way Stopcock with male luer lock | |
| Needles | Tyco Healthcare 8881202389 | Monoject aluminum hub blunt needles, 22Gx, 0.7mmx 38.1mm: for fetal arterial and venous catheters | |
| Needles | Tyco Healthcare 8881202322 | Monoject aluminum hub blunt needles, 16Gx, 1.6mmx38.1mm: for amniotic catheters |
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